The HIV epidemic in adolescents in the U.S. is an expanding problem with an estimated 50% of the new infections occurring in people under 25 years of age. This adolescent epidemic is increasingly female and racial minority with sexually transmitted infections, predominantly heterosexual in females and homosexual in males. The Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) has been specifically designed to support the development and implementation of an adolescent-specific interventional research agenda, primarily in collaboration with existing NIH supported networks. The Adolescent Medicine Leadership Group (AMLG) herein proposed is a composite of leading investigators from the Adolescent Medicine HIV/AIDS Research Network and premier HIV investigators selected for complimentary and synergistic scientific expertise to address a broad behavioral and biomedical agenda. The development and prioritization of the research agenda for the ATN will be accomplished by parallel functioning leadership groups, the Behavioral Leadership Group and the Pathogenesis Leadership Group. These groups will focus both independently and in combination on the research agenda outlined in this proposal. The background, theoretical context, and insight from ongoing studies are presented along with key remaining clinical and research questions. Principles and initial study design considerations are presented and in some cases concept plans for protocols have been developed. The AMLG personnel combined with the structure outlined here are designed to allow for: 1) timely consideration of state-of-the-art interventions pertinent to the adolescent-specific research agenda; 2) maximal multidisciplinary input for study design; 3) the prioritization and rapid development of these interventions to field ready protocols; and 4) enhancing communications with existing networks or other organizations to collaboratively develop studies. The goal of the AMLG is to identify potentially beneficial behavioral, microbicidal, prophylactic, therapeutic, or vaccine approaches which will impact the expanding adolescent HIV epidemic or improve the quality of life of those adolescents or young adults already infected.